Progrès dans le recyclage et la gestion des déchets

Recycling waste has always been a top concern for the paper industry. In this study, the feasibility of using various papermaking byproducts into building materials was independently assessed. For the first time, the enhancement of sample flexibility and texture following the conversion of wastes into cementitious materials was examined. According to the findings, 20% of the waste in an alkali-activated slag slurry is the ideal percentage for manufacturing paper. Wood chips and paper sludge, in contrast to lime mud and bottom ash, considerably increased the slurry's flexibility. When taking into account how adding wood chips affected the optimization of sample texture, the most suitable amount of paper sludge was 5% when the amount of wood chips in the combination was 15%. Alkali that is most appropriate equivalent was 6% and had a 0.9 silicate modulus. The experimental findings showed that papermaking wastes have a lot of potential for use as circular materials.

Water pollution is a concern for the environment that has an impact on the ecosystem and living things. One of the finest methods for removing heavy metals is adsorption. Agro-industrial waste is becoming a low-cost alternative to traditional adsorbents for these contaminants in wastewater because waste recovery is the foundation of the circular economy. Corn, sunflower seed, and pine sawdust residues were tested as potential adsorbents for synthetic aqueous solutions of Ni(II), Zn(II), and Cd (II). To learn more about these residues' structure, content, and adsorption mechanism, characterising efforts were made. The adsorbents' and adsorbates' adsorption capabilities and efficacies were assessed and compared. The results show that all of the biomasses tested are effective substitutes for synthetic materials, with higher adsorption efficiencies. Than 50% Cd was adsorbed first, followed by Zn, and then Ni. When a mixture of all metals was taken into account, adsorption efficiency in sawdust fell at the concentration range examined (as present in real sewage). Finally, clay ceramics (the forerunners of brick) successfully immobilised the heavy metals with an efficiency of over 88.5%. This process would reduce any contamination that might result from the rarely discussed in the literature disposal of used adsorbents.

Meaningful community participation is a challenging, but promising, feature of environmental protection in developing countries such as Kenya and most especially in pollution management. This study employed a descriptive research design. The target population of this study comprised of households’ heads and community leaders as key informants. The sample size of the household heads interviewed were ascertained through the use of Yamane’s formula which arrived at 352 household heads. Primary data was collected through questionnaires which were self- administered with assistance from the research assistants. The study used multiple regressions to establish the relationship between the independent variables and the dependent variables. The study established that there was a positive significant correlation between pollution management and responsible waste management as shown by a correlation figure of 0.715. The study also established that there was a positive correlation between pollution management and participatory planning with a correlation figure of 0. 621, and that there was also a positive correlation between pollution management and participatory budgeting with a correlation value of 0.681.

For effective planning and development of waste management systems for cities, proper quantification and characterization of the municipal solid waste are essential. The objective of this study was to determine the composition and generation rate of household, commercials and institutions solid waste in Metu town as a measure towards effective waste management. Total daily municipal solid waste generated from the town was estimated to be 35,649 kg, among it more than 83% of the waste generated from households, 16% from commercials area and the rest from institutions. The per capita daily solid waste generation for households was 0.378 ± 0.05 kg/cap/day, commercials area and institutions were found to be 0.024 ± 0.01 kg/floor area/day and 0.14 ± 0.05 kg/employee/day, respectively. The Physical characterization showed that biodegradable waste, plastic, paper and cardboard, textile, leather, rubber, wood scrap, sanitary product and metal waste were the constituents of all waste samples in the study area, but in varying proportions. The composition analysis of municipal solid waste showed that more than 50% by weight was biodegradable/organic waste which is valuable resource for recycling in the form of organic fertilizer. Whereas, 25% of waste generated from the town can be recycled at generation level. The calorific/energy value of municipal solid waste revealed that 3,305 kcal/kg for paper and cardboard waste, and 3,819.33 kcal/kg for wood scrap waste which revealed the suitability of the Metu town municipal solid waste as energy recovery option. From the result of this study it can be concluded that, higher biodegradable solid waste and good calorific value of the solid wastes generated in the town the town municipality can recover this waste by introducing an integrated urban agriculture that might convert this waste to organic fertilizer through composting and waste to energy conversion can be an attractive urban waste management option and source of energy as an alternative to fossil-based fuels.